1. Field of the Description
The present description relates, in general, to visual display and projection systems, and, more particularly, to a method and system for projecting light, including video images, onto dynamic features of a surface of water (or other liquid) such as an upper surface of a pool of water or a fountain or curtain of water. The “dynamic features” may be provided with air (or other gas) bubbles that change in size, quantity, and/or location on the liquid surface over time to provide a moving and varying projection surface or target on the liquid surface.
2. Relevant Background
There is an ongoing demand for ways to create visually interesting and exciting displays that involve water. Throughout the world, fountains have been developed and installed that entertain spectators with jets and fans of water that have unique shapes. The fountains may even be operated in time with music and a light show to provide a unique, choreographed display. In some indoor displays, mist screens have been used to provide a curtain that can be used as a display surface using a rear projection system, and such display systems have been used regularly at large trade shows and other events to provide an interesting way to present information and to entertain a crowd.
Current examples of video projections on water screens (mist curtains, fountain jets, and the like) rely on a pre-programming of the water to suit the projected images (e.g., spray water upward where images are projected) and/or pre-programming of the video stream to project onto the water surfaces that are changing over time. The bubbles or agitated portions of the fountain spray or mist screen provide the better surfaces for reflecting the light from the projector, with light striking more laminar flowing portions be transmitted through the water. In many applications, the audience may see the light that is transmitted through the water and the effect or illusion may be spoiled if too much light is allowed through the water-based projection screen. Another issue with such display systems is that the reflected image may be of lower quality if not enough light is reflected or the viewed image may appear to have holes or gaps where less or no light within a projected image is reflected such as in areas with less or no bubbles (or laminar flow).
In contrast, though, larger bodies of water present a more difficult challenge for the designer of a display. For example, a designer may wish to use a body of water in a pool or pond to display light or media (e.g., a video or still image projected from a projector (“projected images”) or may wish to display images in a channel of a water ride as a boat/vehicle carrying passengers travels through the water. The upper surfaces of these bodies of water are generally planar or smooth, and water is generally transparent or at least translucent to light. As a result, light projected onto the surface of these bodies of water is reflected well only at a specific, narrow angle with most of the incident light being transmitted rather than reflected, resulting in a large percentage of the incident light traveling through the water to the bottom of the pool or channel containing the water. At this point, the light may be reflected upward off the bottom to be viewed by spectators (e.g., people on or nearby the body of water).
A display on the bottom or sides of the pond/channel is generally not desirable as the projected content, such as still image or video, appears to be on the bottom of the pool/channel. This may make the image unclear or distorted as it has to be viewed through a depth of water which detracts from its clarity. Further, lighting the bottom of the pond/channel often will be undesirable as this may reveal equipment such as pumps and nozzles used to create a fountain or a track used to move a boat through an amusement park ride. Additionally, these lower surfaces under the water often are not useful for reflecting light in a predictable or desirable manner such as the bottom of a natural lake or river that may have a bottom covered with mud, rock, and plants. As a result, the surfaces of lakes, ponds, and rivers (all of which may be manmade such as a channel defining a river of water for an amusement park ride) have previously not been used as display surfaces for light-based shows or projected media.